The present invention relates generally to automotive windshield wiper systems and more specifically to the construction of connectors for interconnecting components of the linkage of such systems.
In automotive windshield wiper systems, it is relatively conventional to provide a pair of laterally spaced, pivotally mounted crank arms mounted on the vehicle with a first one of them in direct driving relationship with a drive motor and the other connected to the first through a connecting arm extending from one crank arm to the other for following it in reciprocal movement.
Interconnecting the two pivotally mounted crank arms for timed pivotal movement with respect to one another typically involves the use of ball and socket connections between each end of the connecting arm and the corresponding crank arm. While the use of such a connection provides certain advantages in permitting multiple degrees of freedom of motion in the operation of the windshield wiper system, the pivotal freedom afforded by such connections also provides a disadvantage in certain vehicle applications. One example of such applications is that which exists when a wiper system is installed in a vehicle body in the typical fashion at the rear of the engine compartment in an area in which other vehicle components may intrude into the space separating the two pivotally mounted cranks. Such a wiper system packaging constraint necessitates the design of a connecting arm between the two pivotally mounted crank arms which is bowed or has a displaced portion for clearing the intruding component during operation. This connecting arm construction creates an inherently unbalanced condition. This unbalance can cause a rolling movement of the connecting arm about the ball and socket connections at its ends. Excessive rolling movement of the connecting arm can result in interference, noise and inefficient operation of the windshield wiper system. The normal response to such problem includes the provision of close fitting parts in adjacently spaced relationship about the ball and socket connections to limit the degree of rolling movment permitted or the provision of separate spacers and the like to stop the rolling movement of the connecting arm with respect to the crank arms. Such approaches to limiting the rolling movement have been found to be unduly complicated and uneconomical.